AB-02Work out what your wall is made ofRun a magnet or stud detector across the area. A line of screw heads roughly 400-600mm apart means plasterboard on studs. Tap the wall: a dull, solid thud usually means solid brick or block, or dot-and-dab plasterboard over masonry, while a hollow sound between fixed points means a stud wall. Drill a small 3mm pilot hole in an inconspicuous spot: fine timber dust means a timber stud, grey metal swarf means a metal stud, and brick dust or dense plaster with no give means solid masonry. Older properties with uneven, slightly bouncy walls may have lath and plaster, thin timber strips under the plaster, so go carefully and expect the fixing to need to reach through to a stud.